Advancements in the field of autonomous underwater vehicle

This paper presents a survey on optical sensors and methods for 3D reconstruction in underwater environments. The techniques to obtain range data have been listed and explained, together with the different sensor hardware that makes them possible. The literature has been reviewed, and a classification has been proposed for the existing solutions. New developments, commercial solutions and previous reviews in this topic have also been gathered and considered.

Optical Sensors and Methods for Underwater 3D Reconstruction

Camera-based 3D reconstruction of physical objects is one of the most popular computer vision trends in recent years. Many systems have been built to model different real-world subjects, but there is lack of a completely robust system for plants. This paper presents a full 3D reconstruction system that incorporates both hardware structures (including the proposed structured light system to enhance textures on object surfaces) and software algorithms (including the proposed 3D point cloud registration and plant feature measurement). This paper demonstrates the ability to produce 3D models of whole plants created from multiple pairs of stereo images taken at different viewing angles, without the need to destructively cut away any parts of a plant. The ability to accurately predict phenotyping features, such as the number of leaves, plant height, leaf size and internode distances, is also demonstrated. Experimental results show that, for plants having a range of leaf sizes and a distance between leaves appropriate for the hardware design, the algorithms successfully predict phenotyping features in the target crops, with a recall of 0.97 and a precision of 0.89 for leaf detection and less than a 13-mm error for plant size, leaf size and internode distance.

https://www.mdpi.com/1424-8220/15/8/18587/pdf

Structured Light-Based 3D Reconstruction System for Plants

ReviewIntervention AUVs: The next challenge☆☆☆

The ORCCAD programming environment for robotic systems allows users to address automatic control laws in continuous time at the lower levels, and aspects of discrete-time logic at the higher lev els. ORCCAD provides tools of specification, formal verification, simulation, and real-time code generation integrated within a set of dedicated graphical interfaces. Basic robot actions, which are in trinsically hybrid entities, are handled by the ROBOT-TASK struc ture, which smartly interfaces aspects of continuous and discrete time. ROBOT-TASKS are further logically composed into more complex actions, ROBOT-PROCEDURES, through a dedicated lan guage. While system performance can be checked using simula tions, crucial properties such as deadlock avoidance, safety, and liveness can be formally verified at both levels. The approach is illustrated with an underwater inspection mission.

The ORCCAD Architecture

The aim of this study is to propose a 3-dimension reconstruction method of small-scale scenes improved by a new image acquisition method for quantitative measurements. A stereovision system is used to acquire images in order to obtain several shots of an object, at regular intervals according to a predefined trajectory. A complete methodology of 3D reconstruction is exposed to perform a dense 3D model with texture mapping. A first result on natural images collected with the stereovision system during sea trials has been obtained.

/pdf/3d-reconstruction-of-natural-underwater-scenes-using-the-370mecbdwr.pdf

3D Reconstruction of Natural Underwater Scenes Using the Stereovision System IRIS

The main goal of the UNION ESPRIT Basic Research Action is to develop methods for increasing the autonomy and intelligence of underwater remotely operated vehicles (ROVs). The project focuses mainly on the development of coordinated control and sensing strategies for combined manipulator and vehicle systems. Both fundamental theories and methods for the design of these heterogeneous systems are investigated. A complex canonical mission in the field of offshore inspection maintenance and repair tasks was chosen as an integration guideline of all the results.

/pdf/union-underwater-intelligent-operation-and-navigation-1o0olam5pt.pdf

UNION: underwater intelligent operation and navigation

The objective of this paper is to propose an innovative visual servoing method in order to improve the 3D reconstruction of objects for quantitative measurements. The method uses a stereovision system that allows us to obtain several shots of an object, at regular intervals according to a predefined trajectory. In our case, the stereo rig is equipped with two different cameras, consequently the intrinsic parameters are not the same. The first one is fixed while the other one is mounted on a pan and tilt. Simulation and preliminary experiments in laboratory conditions shows the validity of our approach.

Active Stereovision Using Invariant Visual Servoing

Nos recherches menées dans le cadre du projet européen EXOCET/D1, sont nées du besoin d’avoir des outils adaptés pour l’exploitation des images de scènes sous-marines, en appliquant les techniques de vision par ordinateur. Notre but est de développer une méthodologie pour effectuer une reconstruction 3D de structures sous-marines, permettant de réaliser des mesures quantitatives tridimensionnelles. Dans cette optique, nous avons mené des actions de recherche portant sur l’utilisation de techniques d’asservissement visuel afin d’améliorer la reconstruction d’objets 3D. La technique développée permet de réaliser des trajectoires optimales en vue de réaliser une reconstruction précise. Nous utilisons un asservissement visuel à l’aide d’un système de stéréovision monté au bout du bras instrumenté d’un robot. La géométrie de la tête stéréo contraint la trajectoire suivie par les caméras.

http://jnrr05.irisa.fr/document/jnrr-poster-007.pdf

M. Perrier

Papers

3D Reconstruction of Natural Underwater Scenes Using the Stereovision System IRIS

UNION: underwater intelligent operation and navigation

Active Stereovision Using Invariant Visual Servoing

Reconstruction 3D d'objets sous-marins par asservissement visuel